Id honestly be happy with a 4-5% return even but how to guarantee that?
You can't. Nobody can. You just have to accept that as a fact of life.
You can't control or accurately predict the markets. Nobody can.
You can have a view. But you have to accept that you could be wrong.
I have spent (literally) thousands of hours studying investment books and scouring data on the historic returns of various asset classes. And I have no better idea than anybody else what's going to happen tomorrow.
There is absolutely no point worrying about things that are completely outside your control. Zero.
I really hope this doesn't sound like a lecture but I would suggest that you need to strike a balance between doing things that add value to your life today and looking out for your future self.
It's a terrible cliche but prizes really aren't awarded to the richest man in the graveyard.